To be clear, yes. The issue is with how Go's "interface{}"s (and some other types - like slices, etc) work - it's two pointers that can't be written to atomically, which means you can get into a situation where your objects are invalid.
You could argue that this is contrived, but it's also not going to be fixed. This is in contrast to Rust, where there may be implementation flaws leading to unsafety in safe code, but the language retains the right to fix those, even if it breaks code.
Still, I think there's really no question that Go is a major step up over C and C++.
https://blog.stalkr.net/2015/04/golang-data-races-to-break-m...
Here you can find a POC.
You could argue that this is contrived, but it's also not going to be fixed. This is in contrast to Rust, where there may be implementation flaws leading to unsafety in safe code, but the language retains the right to fix those, even if it breaks code.
Still, I think there's really no question that Go is a major step up over C and C++.